If the wiper only hits one side, the arm may need to be removed and reinstalled in a different initial position on the motor drive shaft. If only one end of the wiper blade hits and not the other, the blade may need to be rotated.To do so assumes you have the type of arm that allows the angle to be adjusted. Finally, the length of the arm may be incorrect. Again some arms allow the length to be adjusted. You didn't mention if the blade hit before you changed it, compare all the new parts to the old to see what has changed.
If you paid 80 bucks for a wiper blade, you should look for a new supplier